The stratification is set by a linear background density profile characterized by the Froude number, \(Fr = U_\infty /ND\) , where \(N\)  is the buoyancy frequency. Three levels of stratification are simulated: \(\mbox{\textit {Fr}}=2, 10\)  and \(\infty \) . \(\mbox{\textit {Fr}}=2\)  is close to the critical Froude number \(\mbox{\textit {Fr}}_c = 6/\pi \)  for the 6:1 spheroid at which the suppression of turbulence in the wake by stratification is optimal [1]}. \(\mbox{\textit {Fr}}=10\)  is a moderate level of stratification closer to oceanic values. Finally \(\mbox{\textit {Fr}}=\infty \)  is the unstratified case which will be used as a reference (ONS21).
